Programmed cell death (PCD) also known as apoptosis is characterized by the organized self-destruction of individual cells that may pose a threat to the integrity of the group. It is a well conserved evolutionary trait in both plants and animals alike. This behavior is triggered by a number of environmental stresses, both biotic as well as abiotic components. For example, in large-scale cultivation, algae experience a number of stresses, including nutrient deprivation and photo oxidative damage, which reduce the cell viability.
During commercial cultivation in bioreactors or open ponds, the organism encounters, and is generally able to cope with, many stresses. In certain cases of large-scale cultivation, the organisms die due to PCD as a result of stress, such as, nutrient limitation and the like.
Although PCD is an important natural mechanism for quality control but certain biotechnological production processes favor quantity of biomass yield over quality. Such processes require mass-cultivation of the organism with minimal casualties. One such example of a process that favors quantity of biomass yield over quality is biofuel production from algae. With progression toward inexpensive algal biomass production systems, it is expected that minimal control of culture conditions may lead to increased algal causalities. The development of algal strains better suited to survive conditions of deleterious stress, particularly photo oxidative stress caused by intense light, could have a significant impact on the commercialization of mass-cultured transgenic algae.
Moreover, in such processes where quantity of biomass yield is favored over quality which require the cultivation of algae, it is desirable to have reduced clumping of the algae. Algae has a tendency to form clumps while growing; such clumps restrict the growth of algae, further leading to death via PCD, leading to decrease in the biomass quantity.
There is, therefore, felt a need for a method for reducing clumping and increasing the biomass of an organism.